Vulcanizing apparatus



Nov. 22, 1927. 1,650,078

L. A. LAURSEN VULCANIZING APPARATUS Original Filed. March 20, 1923:j/fr-fi Mf I mz .5 J5 ffi f 25 Patented Nov. 22, 1927.

, 1,650,078, UNITED STATES PATENT-OFFICE.

LAURITS A. LA'UBSEN, OF AKRON, OHIO.

'VULGANTZING APPARATUS.

Original application filed March 20, 1923, Serial No. 626,390. Dividedand this application filed January 16, 1924, Serial No. 686,456. RenewedApril 26, 1927.

The present invention relates to an apparatus for vulcanizing hollowrubber articles, such as the casings for pneumatic tires, and thesubject matter of this application has been divided out of a cop-endingapplication for a vulcanizing apparatus which was filed by me on March20, 1923, Serial No. 626,320.

According to the present invention fluid pressure is provided andmaintained within the rubber article for expanding it into a tightengagement with ,the interior walls of the mold. The use of this fluidpressure results in holding the rubber article or tire against the moldwith a uniform pressure at every point, so that the finished article ortire has no blemishes on the outer face thereof and the percentage ofdefective tires or seconds is very small. y

Her-etofore it has usually been customary to employ a'bag or tube toreceive the fluid where fluid ressure hasbeen used on the interior ofthe rubber article or tire, and one of the objects of the presentinvention is to provide a novel construction which will eliminate thenecessity of using such a bag or tube, and will at the same time providea leak proof mold without the necessity 0 providing .a number ofexpensive groun joints.

Further objects of the invention are to provide 'a vulcanizing apparatusof this character which can be readily assembled and taken apart, whichcomprises few and durable parts, which can be used in the conventionalvulcanizer pots or containers, and which will easily withstand the roughhandling to which such devices are ordinarily subjected when in use. 7

For a full understanding of the invention reference is to be had to thefollowing description and accompanying drawings, in which 1 Figure 1 isa transverse sectional view through a vulcanizing mold which isconstructed in accordance with the invention, showing a tire in positiontherein preparatory to being vulcanized.

. v Figure 2 is a plan view of the mold with portions broken awayandshown in section to illustrate more clearly the various feathroughthe automatic pressure relief valveand associated parts, and

Figure 4 is a rear end view of the pressure relief valve.

Corresponding and like parts are referred to in the followingdescription and indicated on all of the views of the drawings by likereference characters.

Referring to the drawings which illustrate one of many possibleembodiments of the invention, the reference character A designates aconventional tire casing which is adapted to be built up of fabric andrubber compound in accordance with the usual practice in making hollowtire casings. The tire may be of any suitable design or configuration,andis shown in the present instance as provided at its edge portionswith the usual beads 1. It will be understood, however, that theapparatus may be used in the manufacture-ofstraight side tires or anyother design or configuration of tire, as well as for the manufacture ofclincher tires. During the period of curing or vulcanizing the rubbercompound some inert liquid, such' as water is adapted to be introducedinto the interior of the tire A and to be maintained under asuitablepressure so that the tire f will be expanded and held in a firmand unid form engagementwith the interior walls of the mold.

As will be hereinafter set forth in detail, the invention embodies novelmeans for preventing leakage of the water or other fluid from the moldand also for maintaining the proper pressure within the tire.

The tire A is adapted to be fitted upon a bull ring 2, which is providedwith a radially disposed water passage 3 and an air passage 4. The outerperiphery .ofthe bull rin 2 is flared so that it will fit between the sies of the tire casing at the open inner periphery thereof and conform inshape to the converging side walls of the tire. The water passage 3extends radially through the bull ring from the outer periphery to theinner periphery thereof, while the air passage 4 has a curved inner endand leads from the outer periphery of the bull ring to an annular sidegroove 5.

Complemental mold sections 6 and 7 are applied to the tire and bull ringfrom opposite sides thereof and have an annular or ring formation. Theouter peripheral portions of the said 'mold sections have correspondingflat faces or seats which meet in a The mold section 6 is formed at theinner i periphery thereof with a member U-shaped in cross section formedof an inwardly projecting extension 9, and this extension terminates ina lateral flange 10 which has an inward flan e 11, An annular pocket orchamber 12 is thus provided by the inward extension and flanges of themold section 6,

v said pocket being located between the flanges 10 and 11, and the innerperiphery of the bull ring 2 when the mold sections are assembled. Theflange 11 is then in alignment w-th the inner edge of the complementalv:aold section 7, and after being assembled the mold sections may beclamped or held together in any suitable manner, as by means of thebolts 13.

The mold section 7 is provided with an air outlet pipe 14 whichcommunicates with the before mentioned side groove 5 of the bull ring,and a water supply pipe 15 is connected to the annular flange 10 of themold section 6 and arranged to communicate with the annular pocket orspace 12. The air outlet pipe 14 may be provided with a suit able valve16, and in a similar manner the water pipe 15 may be provided with avalve 17. Water is pumped or forced into the mold through the watersupply pipe 15, being first received in the annular pocket 12, and thenflowing through the passage or passages 3 of the bull ring into theinterior of the tire A. The mold is then so arranged that the inlet endof the air passage 4 is toward the top of the mold, so that the airwhich was previously in the mold will escape through the air'passage 4,groove 5 and air outlet pipe 14 as the mold is filled with water. Afterall of the air has escaped and water commences to flow through the airoutlet pipe 14, the valve 16 thereof can be closed. The water valve 17can also be closed after the water within the tire has between thisplate and the extension 9 of the mold section 6. j The tension of thesesprings 20 normally tends to force the packin .ring 18 into operativeposition, and it Wlll be observed that the outer peripheral edge portionof the packing ring extends beyond the backing plate 19-so that thepressure of the water or fluid which is confined within the mold willtend to force the outer edge of the packing ring more tightly againstthe mold section 7 thereby efl'ectively preventing leakage at thisjoint. The water with which the mold and tire are filled is placed undera suitable amount of pressure for the purpose of expanding the tire Aand tightly compressing it against the walls of the mold. Under ordinaryconditions a pressure of about 125- pounds per square inch has beenfound to produce satisfactory results, although a greater or lesspressure may be used as desired or found most satisfactory. Thispressure acts upon the free edge of the packing ring and tends tocooperate therewith to provide a leak proof joint between the inneredges of the mold sections, and it will be noted that the packing ringand parts associated therewith are permanently mounted upon the moldsection 6, so that they are carried thereby and are always in positionto engage the mold section 7 when the various parts of the mold areassembled. The packing elements do not have to be handled separately andwill not cause any difliculty or loss of time in assembling the mold ortaking it apart.

In order to provide for the expansion of the Water as it is heatedduring the vulcanizing process, the mold is provided with an automaticrelief valve 21which is mounted within a hollow protuberance 22projecting from the inner periphery of the mold section 6. The inner endof the valve 21 is tapered and engages a ground seat at the inner end ofthe enlarged opening through the protuberance. A plug 23 is threadedwithin the outer end of the protuberance 22, and a spring 24isinterposed between the said plug and the valve so that the tension ofthe spring normally holds the valve in a closed position. The plu 23 isprovided with a vent opening 25 and in the sides of the valve 21 arelongitudinallyextending channels 26. With this construction it will beobvious that when the valve is held in engagement with the ground seatthe outlet is closed, although if the pressure within the mold becomessufiiciently great to move the valve out-- wardly against the action ofthe spring 24,

the fluid or liquid contents of the mold will escape through the sidechannels 26 of the valve and the vent opening 25 of the plug. The plugis preferably threaded within the protuberance so that it can beadjusted to regulate the tension of the spring, so that-- the valve willopen automatically and re-' lieve the pressure within the mold when theinterior pressure of the mold reaches a predetermined point. As soon asthe ressure has thus been relieved the valve wi lagain be closed by theaction of the spring 24. The water can be initially forced into the molduntil it begins to escape through the valve 21, at which time it will beknown that the water within the mold is under the desired pressure. Anysubsequent expansion of the water which would otherwise tend to increasethe pressure beyond the desired joint will open the valve 21 and permitthe escape of some of the water until the pressure has been lowered tothe desired point. The pressure is thus automatically taken care of bythe valve 21 and the desired pressure maintained within the tire duringthe perior of vulcanization.

The vulcanizing mold can be used in connection with any suitable orconventional form of vulcanizer pot, and if desired, a hydraulic ram maybe used for forcing the mold sections together. A number of the moldsmight be superposed and placed in the ram at the same time, and thevarious molds might be connected in tandem so that they could all befilled with water at a single operation. It will, of course, beunderstood that Where the molds are forced together by a hydraulic ramor other contrivance the use of bolts for fastening the mold sections together may be unnecessary. A

While I have illustrated and described one particular embodiment of myinvention in detail, it will be understood that many modifications andchanges can be made in the details of construction without departingfrom the spirit of the invention, and I do not wish to be understood asrestricting myself to the exact construction which has been shown on thedrawing and described in the application for illustrative purposes.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is,

1. A vulcanizing mold for tires and like articles, includingcomplemental mold sections meeting in a joint and having a chamber atthe joint, and a packing ring arranged within the chamber andoverlapping the 'oint. 2. A vulcanizing mold for tires and likearticles, including complemental mold sections meeting in a (joint andhaving a chamher at the joint, an a packing ring arranged within thechamber to overlap the joint, said packing ring being permanentlymounted upon and carried by one of the mold sections.

3. A vulcanizing mold for tires and like articles, includingcomplemental mold sections meeting in a joint, a packing ring for thejoint, and means for maintaining a pressure within the mold, thepressure acting upon the packing ring to maintain it effectiveto performits packing function.

4. A vulcanizing mold for tires and like articles, includingcomplemental mold sections meeting in a joint, a packing ringoverlapping the joint, and means for maintaining a pressure within themold, the said pressure acting upon the overlapping portion of thepacking ring to maintain it eii'ective to perform its packing function.

5. A vulcanizing mold for tires and like articles, includingcomplemental mold sections meeting in a joint, a packing ringpermanently mounted upon and carried by one of the mold sections andarranged to overlap the other mold section at the joint, and means formaintaining a pressure within the mold, the said pressure acting uponthe overlapping portion of the packing ring to maintain it effective toperform its packing function.

6. A vulcanizing mold for tires and like articles, includingcomplemental mold sections meeting in a joint and having a pressurechamber at the joint, a packing ring arranged within the pressurechamber and extending over the joint, and means for maintaining pressurewithin the pressure chamber, said packing ring being so arranged thatthe pressure in the chamber will force it into operative position.

7. A vulcanizing mold for tires and like articles,'includingcomplemental mold sections having corresponding edge portions which meetin a joint,-a pressure chamber being provided at the joint, a packingring arranged within the pressure chamber and overlapping the meetingedges of the mold sections, mechanical means for holding the packingring in engagement with the edge portion of one of the mold sections,and

means for maintaining pressure within the v pressure chamber, thepacking ring being so arranged that the pressure in the chamber willhold it in operative engagement with the edge portion of the other moldsection.

8. A vulcanizing mold for tires and like articles, includingcomplemental mold sections formed with edge portions which meet in a.joint, a pressure chamber-being provided adjacent the joint, a packingring arranged within the pressure chamber and overlapping the joint, abacking plate engaging one side of the packing ring, means cooperatingwith the backing plate to force the said side of the packing ring intoengagement with the edge portion of one of the mold sections, and meansfor maintaining pressure within the pressure chamber, the free edge ofthe packing ring being subjected to the pressure whereby it is held inoperative engagement with the other mold section.

9. A vulcanizing mold for tires and like articles, includingcomplemental mold sections applied to the tire and formed withextensions cooperating to provide a pressure chamber, said extensionsmeeting in a joint at one side of the pressure chamber,

a packing ring arranged within the pressure chamber and extending overthe joint, saidpacking ring being arranged so that the pressure in thechamber will force it into operative position.

10. A. vulcanizing mold for tires and likeof the packing ring beingexposed to the pressure of the chamber so that it will be forced tightlyinto operative position thereb 11. A vulcanizing mold for tires and likearticles, including complemental mold sections adapted to be applied tothe tire and formed with extensions which cooperate With each other toprovide a pressure chamher, said extensions meeting in ajoint at oneside of the pressure chamber, a. packing ring arranged Within thepressure chamber and overlapping the joint, and means for forcing oneedge of the packing ring against one of the mold sections, the oppositeedge of the packing ring being exposed to the pressure of the chamber sothat it will be forced thereby against the other mold sec-' tion.

12. A vulcanizing mold for tires and like articles, includingcomplemental mold sections meeting in a joint and having a chamber atthe joint, a packing ring in the chamber and adapted to seal the jointagainst fluid leakage, and means in the mold for causing a fluid mediumtherein to act on the ring to maintain it effective to perform itssealing function.

13. A vulcanizing mold for tires and like articles, includingcomplemental mold sec tions meeting in a joint, a packing ring arrangedto seal the joint, the joint having means to cause a fluid therein toact on the ring to cause the ring to perform its sealing function.

14. A vulcanizing mold for tires and like articles, includingcomplemental mold sections meeting in a joint, a packing ring arrangedto seal the joint, the mold having a passage to conduct a fluid mediumto a side of the ring, and means for conducting such fluid medium intothe mold to press on the ring and maintain it effective to seal thejoint.

In testimony whereof I afiix my signature.

LAURITS A. LAURSEN.

